Effect of Pretreatment on Direct Electroless Ni-P Plating of AZ91D Magnesium Alloys

The effects of different pretreatments on deposition velocity and binding force of direct electrdess Ni-P plating(DEN) on AZ91D magnesium alloys were studied.The rough surface offered more binding points,which could enhance the adherence between the coating and AZ91D Mg alloys,but the binding force was much more influenced by the compaction of the coating.The pretreatment with using phosphoric acid and potassium fluoride as acidic bathes was most suitable for DEN AZ91D magnesium alloy.